The most popular songs are danceable, happy and contain sung lyrics.

Popularity
The first thing that stands out is that Roger Taylor is far less popular than Queen and Freddie Mercury. The most popular song by Roger Taylor is Man On Fire and has a popularity of 39. It is part of the album ‘Strange Frontier’ that was released in the UK in June 1984, with Man On Fire single released three weeks earlier. The three most popular songs by Queen are Bohemian Rhapsody, Another One Bites The Dust and Don’t Stop Me Now which all have a popularity of 81. Danceability and popularity seem to be correlated in Queen and Roger Taylor songs; the more danceable songs are also more popular. Within the songs of Freddie Mercury this pattern can not be found.

Instrumentalness
As for instrumentalness, Spotify was not too precise, since the song with the highest score was Seven Seas of Rhye which does have sung lyrics. The other songs at the top, though, are The Ring (Hypnotic Seduction Of Dale), Vultan’s Theme, God Save the Queen and Escape From The Swamp which are all completely instrumental. In the top 10 most instrumental songs, seven are from the album Flash Gordon which is an album made for the like-named science fiction movie. (If you want to know more about this album, check the Queen official site.) In the chromagram of the song Ming’s Theme you will see how different these songs are from more typical Queen songs. It seems that the more instrumental a song is, the less popular it is on Spotify. There is one exception to this rule: Another One Bites the Dust is one of the most popular songs by Queen but has an instrumentalness of 0.312.

Valence
The happiest song according to Spotify is Misfire by Queen. Rain Must Fall is following with only 0.001 points in difference. Both songs have a danceability score above the mean of 0.462. This seems to be fitting the norm; the happier a song is, the higher it rates on danceability. The lowest valence scores are from the songs Ming’s Theme and The Ring (Hypnotic Seduction Of Dale) which also both are very instrumental. The next song with the lowest valence is a more typical song by the band, namely Who Wants To Live Forever. This song also has the lowest danceability score (0.099).

Oldest Queen songs deviate the most from the mean tempo, their recording skills probably have improved a lot.

Explanation
Here you can see the mean tempo, the deviation of each song from that mean tempo, the loudness in opacity and the beats per measure signature in the size of the point. The biggest deviation can be found in the oldest Queen songs, as the darker points are at the top and brighter points are more toward the bottom, or in the songs with either a relatively slow or fast tempo. Older Queen songs were recorded using analog equipment, which may have had limitations in terms of capturing precise tempos. This could have led to more variation in tempo in their older recordings. It might also be, that the earlier songs were even more experimental than later songs and incorporated more styles that suited more tempo changes.

The song with the highest deviation in tempo by Freddie Mercury is a more classical song he released together with the opera singer Montserrat Caballé. In the tempogram you will also see how hard it is to extract the tempo using computation.

Time signature
Spotify API had a hard time with the songs Execution of Flash as well as Ming’s Theme by Queen because there is no consistent time signature. The album Flash Gordon once again stands out, both of these songs are part of it, and as you will see in the chromagram section, this is not a typical album. The song Dear Friends by Queen also stands out; it states that there is only one beat per measure but when I listened to the song, I felt like the time signature was 4/4. I do have to say that the arrangement with the piano emphasized all beats very equally, that might be an explanation for the weird time signature.

After Freddie Mercury’s death, the sadness could be felt in the songs by Queen.

Emotion Model
I was curious about the emotion every song portrays. Freddie Mercury has once said that he is very emotional. “I think all my songs are under the label emotion. The more I open up, the more I get hurt, so basically what happens is I’m just riddled with scars.” After Freddie Mercury’s death, I could see songs portraying more of a sad emotion. Since emotion is very complex, I have decided to simplify this by plotting the valence (positive and negative) against the arousal (for which I have selected high and low energy). This way, the songs are plotted on the 2D valence-arousal model of Emotion in which each quadrant stands for a different type of basic emotion (angry, happy, sad, peaceful).

Explanation
There seem to be very few peaceful and calm pieces, which corresponds to the characteristics of the band. The only songs that are in this category are from the band with Freddie Mercury as lead singer. After the death of the singer, there seems to be a slight shift towards sad and angry songs. Roger Taylor has more turbulent songs, while Freddie Mercury also has quite a few sad songs.

Note
The plot can be a little seem a little overwhelming and cluttered, but you can filter artists out by clicking on them in the legend or even isolate them by double tapping them.

Timbre features reveal the difference between old and new Queen songs.

Explanation
For every 12 levels of timbre used by Spotify API I have plotted the range for the songs by Freddie Mercury, the oldest songs by Queen (released around the year 1973) and the newest songs with Freddie Mercury still as lead singer (released around the year 1990).

According to the clusters, some of the timbre levels should be very distinct between the three categories I plotted. For example, from most useful to less useful, the levels 4, 12, 3 and 1 should be quite different. Unfortunately, timbre is a very abstract term to talk about music. According to Jehan (2014) timbre “is the quality of a musical note or sound that distinguishes different types of musical instruments, or voices.” Spotify uses 12 different levels to quantify timbre, the first of which is easy to understand, but that goes down very quickly. Level 1 represents the average loudness of a section and the second level calculates the difference in energy between lower and higher frequencies (this should represent the brightness, which is already much less concrete). The next dimension does this for the mid-frequencies (which should correlate to the flatness of the sound) and the fourth represents the energy of the attacks (the beginning of sounds).

As I have already said in the introduction, the first few songs sound less clear than all songs that come after due to reverb on the vocals and guitar. I think this relates to the brightness, flatness and attack of the tracks, which as you can see, all seem to differ quite a bit between the first 25 songs and the last 25 songs of Queen. Specially the fourth dimension, where the old songs have range much lower than both the older songs and Freddie Mercury songs. Freddie Mercury songs seem to have more overlap with the older songs except for the second dimension. I think the songs by Freddie Mercury have a huge range in this dimension because of the operatic songs that have more energy in higher frequencies and the electronic songs that have more energy in lower frequencies.

Reference
Jehan, T., DesRoches, D. (2014). Analyzer documentation (analyzer version 3.2). Accessed 27 Mar. 2023

Chromagram of a very atypical song by Queen (Ming’s Theme) shows simplicity.

Chromagram
I have created three chromagrams to show the difference between a simple, atypical Queen song and complex Queen and Freddie Mercury songs that are very representative for their style. A chromagram shows the the energy for every pitch class during a song.

Explanation
A very atypical song by Queen is Ming’s Theme (In The Court Of Ming The Merciless). This song is part of the album that was made specifically for the movie Flash Gordon. It starts with low pitched electronic sounds and later on includes people talking. In the chromagram you can see how the song starts on a note that is somewhere around F sharp. There are two descending melodies leading to a note between C and C sharp. After this, the talking starts with the same note softly sounding in the background. Around two minutes into the song there is another descending melody. The melodic part ends with a perfect fifth (D and A). The song concludes with a dialogue from the movie.

Comparison
On the next page the chromagram of Don’t Stop Me Now and I Was Born To Love You can be seen. You will see that this clear distinction of notes and sections can not be made in a more typical Queen song, also in a Freddie Mercury song this is much harder. Even the key can not be easily identified.

Typical Queen and Freddie Mercury songs, however, are far from simple.

Queen
For Queen, I think Don’t Stop Me Now is a very representative song. It is very energetic, melodic and euphoric. It is also one of the most popular songs according to Spotify, along with Bohemian Rhapsody and Another One Bites The Dust.

Freddie Mercury
For Freddie Mercury as a solo artist I have chosen the song I Was Born To Love You, as it is the most popular song according to Spotify. I also think it is quite representative for Freddie Mercury, as it has a disco feeling and is very lively. The song The Great Pretender is equally popular, but is a song originally by The Platters and written by Buck Ram (their manager).
I have also plotted The Great Pretender as a chromagram (can be seen on the next tab) and interestingly this was much more readable than original Queen and Freddie Mercury songs, just like Ming’s Theme.

Comparison
The chromagram shows that Don’t Stop Me Now contains lots of pitch classes and it has thus very complex harmonies, while I Was Born To Love You seems to have a bit more of distinct pitch classes with high energy. The highest energy can be found in the class of G sharp, this is also the key of the song. For Don’t Stop Me Now it is harder to see the key, though the pitch class G seems to have a slightly bigger magnitude than the other pitch classes, this song is in the key of F major.

The chromagram of The Great Pretender originally from The Platters by Freddie Mercury.

Explanation
As said before, this song is originally by the Platters and covered by Freddie Mercury. In the chromagram you can clearly see that the song starts in G major from the frequent bright yellow stripes, meaning that there is most energy in the pitch class G, and modulates at the red line to G sharp major. The pitch classes C and D are also used repeatedly in the first 120 seconds. Freddie Mercury loved the song The Great Pretender for its meaning as he felt like he played different roles on stage; he went through different moods, wore different costumes and became someone else with each costume.

Conclusion
Both Queen and Freddie Mercury songs are known for the intricate harmonies, which the chromagrams seem to confirm. Though the solo work might be slightly less complex and sometimes a little more stripped down to focus on the rhythm and energy.

Queen songs tend to deviate from the clear structure that is frequent in popular music, unless Roger Taylor writes the song.

Self-similarity matrices
These are four self-similarity matrices, with the axes in seconds, that show the pitch- and timbre-based self-similarity for every bar. At the top you can see a song that is written and sung by the drummer Roger Taylor but released as a Queen song. On the bottom the song Bohemian Rhapsody, written by Freddie Mercury, can be seen. The song written by Roger Taylor seems to have much more of a uniform structure than Bohemian Rhapsody, which can be derived from the checkerboard pattern.

Explanation
The song I’m in Love With My Car starts with a guitar riff accompanied with repeating D chords on the piano, followed by verse 1 that makes use of four different chords that are repeated after one another. After 60 seconds, the chorus starts in which Freddie Mercury sings backing vocals. There is a slight change in color in the timbre-based matrix, but I expected to see a greater change. The chords stay the same, thus the transition from verse 1 to the chorus is not really visible in the chroma-based matrix. At around 1:20 minutes (80 seconds) into the song, the chords change. This can be clearly seen in the chroma-based matrix, but is less apparent in the timbre-based one. That the guitar riff and accompanying piano chords recur after this short change becomes evident from both matrices. Then there is another verse that follows the same structure as verse 1, but does include guitar riffs in the background. The two matrices pick up the repetition in the second chorus very well, resulting in diagonal lines at around 2:10 minutes (130 seconds). They play once again some guitar riffs accompanied by the repeating chords on the piano that slowly fade out with car noises sounding on top of that. The song ends with some chords on the guitar that sound very different (which explains the bright yellow line at the end of the timbre-based matrix) and car noises.

Songs by Freddie Mercury as a solo artist also have a clearer structure.

Comparison
As I explained in the introduction, Queen is known for their experimentation and deviation from the norm. On the previous tab this could be seen in the matrices of the song Bohemian Rhapsody, since there was some structure visible but not how you would expect a typical rock or pop song to be arranged. The song that was written by Roger Taylor had much more of a common and clear structure, as is the case with a very typical song by Freddie Mercury as a solo artist. On this page you can see the timbre- and pitch-based self-similarity matrices of the song Living on My Own. The song is in my view a classic Freddie Mercury song, that features Freddie’s distinctive voice, flamboyant personality, and his love for dance music. The song’s upbeat tempo, catchy melody, and electronic production are all hallmarks of Freddie’s solo work. Additionally, the song features a memorable chorus, which is typical of Freddie’s ability to write catchy songs.

Freddie Mercury
The chroma-based matrix illustrates nicely through the diagonal lines that there are lots of repetitions in the song. The songs starts with A minor chords and when the next chord is introduced, there is a yellow line in the chroma-based matrix (at around 25 seconds). At around 50 seconds, the chorus is introduced. In the same matrix it becomes clear that the chorus repeats after another 35 seconds (approximately 85 seconds into the song). Next there is a break with some scatting and improvisation on the piano, followed by halve of the chorus. The beat that is used throughout the whole song accompanied by piano chords and some occasional scatting are utilized as an outro. Though the true ending is the artificial repetition of one ad lib by Freddie Mercury.

And here is an extra, interesting self-similarity matrice of an atypical song by Queen written by Brian May.

Explanation
Coincidentally, this song is also not written by Freddie Mercury but by Brian May. I found this song very interesting, because of it deviates greatly from the normal style of Queen. It is a blend of folk and progressive rock with acoustic instruments, vocal harmonies, and storytelling lyrics. At around 35 seconds into the song the beat comes in. This interestingly leads to a change in the chroma matrix but a much less clear change in the timbre matrix. After one and a half minutes the bridge introduces new chords. I find it very strange that this is so clear in the timbre matrix but not in the chroma matrix. It almost feels as though the matrices are switched around. Specially because the bright yellow cross in the chroma matrix is exactly where the electric guitar makes an appearance.

Queen songs can be structured, but they find a way to still make the song interesting.

Conclusion
Once again this electronic dance song by Freddie Mercury shows a noticeable structure with some diagonal lines indicating repetition, here of the chorus.

The song Innuendo by Queen, on the other hand, shows a very nice checkered pattern at the beginning and end, but there is a very different part in the middle. I think this is a good summary of Queen; some song will have a clear structure but they will always find a way to still make the song interesting, whereas Freddie Mercury’s songs are sometimes a little more simple and rhythmical. I also wanted to note that besides the structure of the song by Queen, the vocal performance is also very impressive which is typical for Freddie Mercury in general. “[Innuendo] would prove to be the last album Freddie worked upon and yet also, despite his palpably deteriorating health, a work containing some of his most powerful and emotive vocal performances of all.” as Queen said themselves. Definitely have a listen if you are not familiar with the song!

The seemingly structured song Innuendo (according to the self-similarity matrices) has a difficult tempo to detect.

Tempogram
A tempogram shows for every possible tempo how well it matches with the song. A good match turns up bright yellow and everywhere you see dark blue, the tempo does not lign up with the song.

Explanation
In the self-similarity matrices I ended with the song Innuendo by Queen. Even though the song has a very clear drum and rhythm, the drum does make use of triplets which probably makes it more difficult to detect a uniform tempo. When the very contrasting bridge starts (at around 2:45), they start with a low energy guitar with hints of flamenco along with soft vocals by Freddie Mercury. In this section the rhythm sometimes slows down or speeds up to match the dynamics of the vocals and other instruments, also known as rubato. Despite the fluctuation in tempo, this section does seem to have a lower tempo which can also be seen in the figure (there are more bright yellow bits between 80 and 120 BPM then before). Just before the 200 seconds mark, the speed picks up and you hear guitar and clapping. Brian May incorporates Spanish guitar techniques such as tremolo picking and arpeggios, which are commonly found in Mediterranean and flamenco music. Flamenco music is also very rhythmic; as you can see in the graph, this part has a much clearer tempo though still not a very consistent tempo. Another section starts at around 236 seconds, which is a sort of classical, operatic, walz part.
This tempogram shows that despite the seemingly clear structure the song has according to the self-similarity matrices, there is definitely a lot going on in terms of rhythm and tempo.

The song that was written by Roger Taylor has a clearer tempo in the tempogram.

Explanation
This clearly structured song (as could be seen in the self-similarity matrices) written by Roger Taylor has faintly more of a clear tempo. The uptempo rock song has a driving rhythm and features Taylor’s vocals and a prominent guitar riff from Brian May. The lyrics are about Taylor’s love for his car and as I said before, the song also includes some car sounds, but that did not change the accuracy of the tempogram.

As you shall see, the tempo might be more clear than the tempo in the previous song because the song is more focused on the percussion, but it is certainly not as unambigious as the following electronic songs by Freddie Mercury.

The disco songs by Freddie Mercury are much easier to plot in a tempogram.

Explanation
All these songs are solo songs by Freddie Mercury. The bottom two are part of the album Mr. Bad Guy, the other two are singles. The songs are very electronic and disco inspired. As Freddie Mercury said himself: “I wanted to cover such things as reggae rhythms and I’ve done a couple of things with a symphony orchestra. It has a very rich sound and it’s very beat orientated.” Electronic, beat orientated songs such as these four are very likely to have a clearly visible tempo. Thus, I was also curious about a very different song, namely Barcelona, which you will see in the next tab.

The song Barcelona by Freddie Mercury and opera singer Montserrat Caballé is all over the place tempo wise.

Explanation
The song Barcelona is very “un-rock ’n’ roll” as Freddie Mercury stated himself, just like the rest of the album. It “really required a lot of discipline” and “[the] ideas […] underwent significant changes along the road to perfection.” (Freddie Mercury’s official site). In other words, Freddie Mercury put a lot of time and effort in the songs on the album Barcelona to create something really unique. The album incorporates lots of classical elements with more traditional pop characteristics. Classical music often features multiple layers of melody and rhythm that interact in complex ways, and this can make it difficult to separate out the different elements of the music and plot them in a coherent tempogram. This can be seen in the tempogram of the song Barcelona.

The distribution of tempi for each artist deviates from the preferred tempo.

Conclusion
Interestingly, even though according to Dirk Moelants (2002) the preferred tempo is between 120 and 130 beats per minute (BPM), in this plot you can see that most songs are around 80 BPM. This is relatively slow and specially for the many disco inspired songs by Freddie Mercury. The most frequent tempo is around 110 BPM for Queen, and 160 BPM for Roger Taylor, but Queen has a more normal distribution and the drummer’s songs are very evenly distributed.

I think we can say that Queen songs are overall a little hard to plot in a tempogram (which also ties back to the amount of standard deviation in the general tempo plot) while Freddie Mercury songs either have a very easy tempo to detect, as in his electronic disco songs, or songs in which the tempo is more complicated to plot in a tempogram, such as the more classical songs.

Reference
Moelants, D. (2002). Preferred tempo reconsidered. C. Stevens, D. Burnham, G. McPherson, E. Schubert, J. Renwick (Eds.), Proceedings of the 7th International Conference on Music Perception and Cognition. Sydney, Adelaide, Causal Productions, 580–583.

Two chordograms of balads: Love of My Life and Time Waits for No One.

Chordogram
These chordograms show the similarity for every bar of a song with certain chords. The more similar the bar is to that specific chord, the darker the color in the graph. When you see bright yellow, it is very unlikely that chords was played in that bar.

The two songs are, in my opinion, quite similar in style. Both ballads have intricate piano arrangements and are a little more stripped down compared to the rest of the discography. That is why I thought it would be interesting to see how the chordograms compared to one another.

Time Waits for No One
Even though the plot looks quite clear, it is still harder to get all the right chords since Freddie Mercury composed a complex piano arrangement that has multiple chords (and definitely not only simple triads or triads with the added 7th note) in one bar. I think that the fact he only uses piano to accompany his vocals makes it seem easier to plot in a chordogram, however, the dark blue boxes are all over the place and not very accurate.

Love of My Life
At first glance it looks a little messy to me, but after listening to the song and having a closer look at the plot I came to the conclusion that the plot accurately shows that the song makes use of only a few chords and I discovered that the start of the song was the clearest. The song starts with an instrumental introduction that ends with an arpeggio G major chord on the harp which can also be seen by the dark blue box at 20 seconds. When Freddie Mercury starts singing (after the arpeggio) the accompanying chords are C, Am, Dm, G and then C, F, Dm, Am, B♭m, F which I could also find in the figure. However, after the first yellow line, which can be explained by the piano riff that is played, the plot gets a little more muddy. There is another instrumental bit that focuses more on melody than on triads and the second yellow line is created by the walking bass line. At around 1 minute and 47 seconds, the third yellow line, there is a guitar riff preceded by piano riffs with walking bass lines. From 2 minutes and 20 seconds you can hear a guitar solo. At 2:27 (fourth yellow line) there is one sustained guitar note (with some piano notes accompanying). After 193 seconds there is another arpeggio that results in a dark blue box on F major.

Comparison
Overall, I think that Love of My Life seemed a little harder to plot in a chordogram because of the instrumentation, but was in the end more accurate than Time Waits for No One because there are less different chords in one bar.

Electronic disco song Let’s Turn it On by Freddie Mercury leaves weird pattern on all 7 chords.

Explanation
I think it is interesting to see that in this very electronic song, there is not a clear pattern in the chords, whereas in the former two figures there was some sort of dark blue path throughout the plots. All chords that include the 7 have a darker blue line across the entire plot, which is explainable by the way pitches are constructed.

This song from the 85’s was released on his solo album Mr. Bad Guy and is just like the four songs in the tempograms a high-energy disco track with a prominent bassline, synth-heavy instrumentation, and Mercury’s signature vocals. Though there seems to be not much going on harmony wise, Freddie Mercury still has managed to make the song very interesting through syncopation and layers of synths, guitar, and percussion.

Chordogram of Bohemian Rhapsody.

Explanation
Since Bohemian Rhapsody is such a complex song, I wondered what it would look like in a chordogram. There are not many chords with high energy and there is definitely not a clear pattern as was the case with the first two plots. But I am able to see some of the structure of the song in the plot. The song starts with the vocal arrangements and where the bright yellow lines are visible, the bass comes in. After that there is a slight change where the operatic part begins. Interestingly, when they transition to the rock part, there is not as much of a change in the graph. The outro looks much more like the intro as this part is once again much more stripped down mainly focusing on vocals and a piano arrangement.

Conclusion
I think there are mainly two styles Freddie Mercury went for in his solo career: either focusing on elaborate arrangements, in the piano or in vocal harmonies, or giving more of a disco feel by using a steady beat and electronic sounds in the harmonies. Queen as a band naturally made arrangements that highlighted all of the members and their instruments. Which might be an explanation why Love of My Life has a little less of an intricate piano arrangement and was thus more accurately plotted in the chordogram than Time Waits for No One.

After the death of Freddie Mercury the band released most songs in G major, just like Freddie Mercury in his solo career.

Explanation
Here you can see the distribution of keys for every artist. In the next tab you can see the actual amounts (which can also be seen in if you hover over the points), but as there is such a difference in playlist length (see the table), I have chosen to first plot the ratio.

Interestingly, the key G major was very loved by Freddie Mercury, Roger Taylor and the band after the death of the lead singer. When Freddie Mercury was still in the band, the key D major the most frequent. And overall, Queen seemed to use more major keys than minor keys. After all their music often has a uplifting and joyful feeling which generally goes hand in hand with a major key.

Number of Tracks per Artist

Distribution of keys for every song in actual amounts.

Numbers of Tracks per Artist

Freddie Mercury produced operatic pop, electronic disco and experimental pop music.

Dendrogram
In a dendrogram, items that are the most similar get clustered together. The longer the paths and thus the further the connection, the less similar the items or clusters are. I have used all features that are within the Spotify API to cluster Freddie Mercury’s solo songs.

Freddie Mercury
I like how you can see the more classical songs, the electronic disco songs and the remaining songs clustered. Both albums seem to have pretty much their own distinct sound. Except for the song Mr. Bad Guy which includes lots of orchestral instruments and therefore gets clustered together with two more classical songs from the Barcelona album. She Blows Hot and Cold stands out, it is kind of the only outlier. It is much more generic pop-rock and definitely not like the electronic songs on the Mr. Bad Guy album. The song In my Defence was not written by Freddie Mercury. Dave Clark wrote it for the musical Time but the song still suits the singer very well. I am not surprised it was clustered together with the song Made in Heaven, as this is as much of a grand, theatrical and powerful song.

Queen and Roger Taylor
I have also checked the clusters of Roger Taylor and Queen - because of the big amount of tracks, both are very cluttered and thus I decided not to include them - which had much less clear clusters than the dendrogram of Freddie Mercury. However, one album by Queen very much stood out; Flash Gordon was almost completely isolated from the rest of the tracks. The two most similar songs by Queen were These are the Days of our Lives and Delilah. After listening to the songs, I can see the similarity in timbre but not much further than that. The two songs ’39 and Leaving Home Ain’t Easy were also clustered together. Both songs are written and sung by Brian May and have a lot of country influences.

Clustering early Queen, late Queen and Freddie Mercury leads to three main clusters.

Explanation
In this dendrogram you can find all 25 tracks by Freddie Mercury I put in the playlist compared to the first and last 25 songs by Queen using all the features Spotify API has to offer.

Brighton Rock looks a bit like an outlier, as well as Procession (both have rather long branches), which are two songs from Queen in the early days. You will see on the next page how Procession is very different from the rest loudness wise. Brighton Rock tells a story about two lovers who meet in Brighton. If you listen to the song you can hear how they wander across the street on a national holiday, while street musicians are playing. The excitement but also rebellion are portrayed by the energetic guitar riffs that Brian May was able to play.

Conclusion
Overall, most Freddie Mercury songs are clustered together and the earlier Queen songs too. The oldest Queen songs are a bit mixed together with Freddie Mercury solo songs.

Telling Freddie Mercury apart from Queen is not very hard.

Confidence matrix
Based on the features danceability, energy, loudness, speechiness, duration and timbre component 4, I made a model to predict whether a song was by Freddie Mercury, early Queen or late Queen. These features were the most important besides some other timbre features. I once again put in all 25 songs by Freddie Mercury and the first and last 25 songs by Queen. Here you can see how well the model did; the number in the cells show for every combination (the three true categories and how the three categories were predicted) how often this was the case. For example, the first value (upper left corner) shows the number of times the model predicted correctly that a song was by Freddie Mercury, the value immediately below shows for every Freddie Mercury song number of times it predicted it was an early Queen song and underneath that the times that it predicted it as a late Queen song. Classifying Freddie Mercury seems to be the easiest. But both the earliest and latest songs by Queen were apparently also not too hard to classify, since the model predicted most songs right. This could also be expected based on how the dendrogram on the previous page already seemed to cluster most of the songs by artist somewhat right.

Precision is the proportion of accurately predicted songs from all songs the model predicted to be from that artist. Recall shows from all songs that are actually from that artist the proportion that got predicted accurately. As you can see, the model using only the most important features has both higher and lower values and thus does not necessarily perform better than the model using all features Spotify API has to offer.

Earlier Queen songs lack sharpness and Freddie Mercury songs are less loud.

Explanation
The most important feature to tell Freddie Mercury apart from Queen is timbre level 4, which shows the energy in attacks of sounds which might translate in more abstract words to the sharpness of sounds. Outside of the timbre features, loudness, danceability and speechiness were most important.

Once again, the first few songs definitely sound different from the older songs and from Freddie Mercury songs in terms of clearness. The older songs sound a little more muffled and have more reverb on the vocals and guitar. However, when I listened to the songs with the highest and lowest value on timbre component 4, I noticed that the higher the value, the more kick there was in the song and specially in the beat. In other words, My Baby Does Me has a very strong beat with a sharp and high energy snare. When listening to Some Day One Day which according to the plot has the lowest value on timbre component 4, I heard that all sounds have the same energy. There is no sharp beat and it does sound a bit flat and lacks dynamics.

The song Procession by Queen has the lowest energy and that is very noticeable if you listen to the track. It starts with simply a soft beat and after that only features a guitar that sounds a bit in the distance. This might also be because the track is heavily panned to the left at the beginning and to the right from the second half.

Classifying Queen after the death of Freddie Mercury is much harder.

Explanation
I also wanted to know whether Roger Taylor could be as easily classified as Freddie Mercury and the band. Once again, Freddie Mercury was classified very well and the same holds for early Queen. Later Queen and Roger Taylor were a little less accurately classified, but not nearly as bad as Queen after the death of the singer. The few songs that were released in honor of Freddie Mercury have more in common with the solo songs by both Freddie Mercury and Roger Taylor than the songs by Queen as a band.

Are Roger Taylor’s songs less intense than Queen songs? Have a listen!

Explanation
In terms of timbre, the groups are quite distinguishable as you can see in the plot and in the former tab. As I have mentioned before, what this exactly means is very hard to say as timbre is very abstract. Spotify uses 12 different components to calculate timbre, which get more abstract the higher the level. Therefore, you can probably imagine that timbre component 9 is very incomprehensible, in fact, there is not even a description of it. I am not able to fully grasp how this timbre dimension works, as the song by Freddie Mercury with the highest value is Guide me Home, which is very much a classical song. While The Hitman and Ogre Battle are two of the most heavy songs by Queen that lean towards metal, and also have a high value. However, I do think that those songs are more intense in some way than the song with the lowest value Magic is Loose

Conclusion
Even though I might not be able to hear a clear difference with regard to timbre component 9, the five categories seem have enough differences to be classified reasonably well. After the death of Freddie Mercury the band released one last album with demo’s and ideas that Freddie Mercury recorded when he didn’t have long to live. That some songs are classified as solo songs by Freddie Mercury is not surprising as the band members used unreleased work and songs from Freddie’s solo career, which are infused with the signature sound of the band. You can read more on this (in Dutch) on the Radio Veronica site.